USPS 955 Certification

What USPS 955 Certification Actually Is

USPS 955 is the maintenance selection exam the United States Postal Service uses to screen candidates for skilled craft and technician positions inside its Maintenance Selection System. It's governed by Handbook EL-304, and unlike many employment assessments, it isn't outsourced to a commercial testing vendor - USPS delivers it directly at approved test centers as a proctored, computer-based exam. You'll need valid photo identification to sit for it, and there is no cost to take it. USPS is explicit that it never charges for exams, applications, or employment information, and the Postal Inspection Service treats any request for exam payment as an employment scam.

If you're still getting oriented to the basics, the companion piece What Is USPS 955? and the plain-language breakdown at USPS 955 Meaning are good starting points before you dig into domain-level prep.

Exam Structure: Two Parts, Two Different Skill Sets

The official USPS Assessment Information Package for Exam 955 defines exactly two parts, and understanding the split matters because the parts measure completely different abilities.

• Multicraft: 60 items in 60 minutes, assessing mechanical and electrical job skills drawn from real craft knowledge.
• Spatial Relations: 68 items in 40 minutes, divided into Matching Parts and Figures (deciding which figure shows how loose pieces fit together without gaps or overlap) and Spatial Visualization (deciding which solid would produce the top, front, and right views shown).

Total testing time runs roughly two hours. Because the two parts test such different mental skills - one recalls technical facts, the other manipulates shapes mentally - treating them as a single undifferentiated "study for the test" task is a common mistake. For a full walkthrough of pacing and item types, see USPS 955 Study Guide 2026: How to Pass on Your First Attempt.

The 9 Content Domains You'll Be Tested On

USPS 955 content is drawn from 21 technical fields covering roughly 131 topics, mixing hands-on craft knowledge with the underlying science behind it. For prep purposes, that content maps cleanly onto nine domains:

Note that USPS reports content-area performance only in High, Average, and Low bands - it publishes no percentage weighting per knowledge area, so you can't "over-invest" in one domain based on an official weighting because none exists. For a deeper dive into how these nine domains interact and how to sequence study across them, see USPS 955 Exam Domains 2026: Complete Guide to All 9 Content Areas.

Registration, Fees, and the 120-Day Retest Rule

There is no cost to sit for USPS 955. That single fact eliminates an entire category of scams targeting job seekers - anyone asking you to pay for the exam, an application, or "priority" employment information is not USPS. The full mechanics of scheduling windows and open seasons are covered in USPS 955 Exam Dates 2026: Testing Windows, Deadlines & Scheduling, and a plain accounting of what you will and won't spend is in USPS 955 Certification Cost 2026: Complete Pricing Breakdown.

Handbook EL-304 sets a 120-day retest rule:

• Entrance applicants who reapply may retake the test or reuse their existing score if they apply 120 days or more after their original exam date.
• In-craft (in-service) candidates testing for a score update may reschedule 120 days after the original exam date.

Entrance ratings carry an expiration date printed directly on your Notice of Results, so track that date carefully. In-service scores, by contrast, remain valid indefinitely unless the examination requirements themselves change. This distinction matters a lot for anyone weighing whether to apply as an external candidate or wait for an internal open season - a topic covered in more detail in USPS 955 Requirements 2026: Eligibility, Prerequisites & How to Qualify.

Scoring, Veterans' Preference, and What "Passing" Means

USPS 955 uses a rating scale from 70 to 100. A minimum score of 70, excluding Veterans' Preference points, is required just to be considered for any position you've applied for. Veterans' Preference points are added only on top of an already-passing score - they cannot turn a failing result into eligibility. The exact numeric mechanics, including how points get applied to a raw score, are broken down further in USPS 955 Passing Score 2026: Exactly What You Need to Pass.

Because there's no per-domain percentage breakdown published, don't expect a score report that tells you "you scored 40% on hydraulics." You'll see High, Average, or Low bands by content area instead, which is enough signal to know where to focus if you retest. If you're trying to gauge overall difficulty before you commit study hours, How Hard Is the USPS 955 Exam? Complete Difficulty Guide 2026 and USPS 955 Pass Rate 2026: What the Data Shows are worth reading alongside this section.

Jobs You Can Qualify For With a Passing Score

USPS 955 isn't tied to a single job title - it feeds the entire Maintenance Selection System. Positions filled through this exam include:

• Electronic Technician, PS-10 and PS-11
• Maintenance Mechanic, MPE
• Area Maintenance Specialist
• Building Equipment Mechanic
• Maintenance Electrician
• Machinist
• Carpenter
• Mason
• Plumber
• Painter
• Blacksmith-Welder
• Letter Box Mechanic
• Building Maintenance Custodian

There are no formal education prerequisites to sit for the exam - it's open to external entrance applicants and to current employees during the Maintenance Craft in-service open season. That open-access structure is exactly why the exam's technical breadth (21 fields, ~131 topics) matters so much: it's screening for a wide range of trades in a single test rather than one narrow specialty. For a fuller picture of which roles align with which strengths, see USPS 955 Jobs, and for a longer-horizon view of what these roles pay over time, USPS 955 Salary Guide 2026: Complete Earnings Analysis is a useful companion read.

Preparing Around the Domains, Not Around Generic Advice

Generic study advice - flashcards, timed drills, spaced review - only helps if it's mapped onto the actual structure of Exam 955. A simple way to sequence eight weeks of prep against the domains above:

Notice the Spatial Relations domains are deliberately pushed to the final stretch - that section is 68 items in only 40 minutes, so speed under pressure matters more than long-term retention, making it better suited to concentrated practice close to your test date. Multicraft content, by contrast, benefits from earlier and more distributed review since it draws on 21 technical fields you can't cram effectively in a week. If you want a compact reference to run through in the final days, USPS 955 Cheat Sheet 2026: One-Page Review of Must-Know Facts condenses the highest-yield facts, and you can build timed reps for both exam parts using the practice tests at postal955exam.com.

If you're still weighing whether the time investment is worthwhile given your career goals, Is the USPS 955 Certification Worth It? Complete ROI Analysis 2026 lays out the tradeoffs without inflating expectations. And if terminology is still confusing you - especially given how many unrelated credentials share the "955" label - What Does USPS 955 Mean? and What Is USPS 955 Certification? clarify the distinction directly.

Frequently Asked Questions