По истечении месяца заявитель предъявит медицинскую справку.

По истечении месяца is a formal, bureaucratic way to say after a month has passed or upon the expiration of a month.

A more everyday Russian way would often be через месяц (in a month) or sometimes спустя месяц (a month later). But по истечении месяца sounds especially official and is common in legal, administrative, and written instructions.

So the difference is mostly one of style and register:

• по истечении месяца = very formal, official
• через месяц = neutral, everyday
• спустя месяц = natural narrative style

In documents, Russian often prefers these more formal expressions.

Истечении is the prepositional singular form of the noun истечение (expiration, lapse, elapsing).

The expression по истечении is a fixed official phrase. Literally, it is something like upon the expiration or after the lapse.

Here is the basic form change:

• dictionary form: истечение
• in this phrase: по истечении

This is one of those expressions that learners often just memorize as a set phrase:

• по истечении срока = after the term has expired
• по истечении года = after a year has passed
• по истечении месяца = after a month has passed

Месяца is in the genitive singular because it depends on the noun истечение.

The logic is:

• истечение чего? = the expiration/lapse of what?
• месяца = of a month

So:

• по истечении месяца = upon the expiration of a month

This is a normal noun relationship in Russian: one noun often requires another noun in the genitive.

Compare:

• конец месяца = the end of the month
• начало года = the beginning of the year
• истечение срока = the expiration of the term

Заявитель means applicant, claimant, or person submitting an application/request, depending on context.

It is a formal word, common in:

• legal language
• administrative procedures
• immigration or visa paperwork
• court or government documents

It is not the most common everyday word for person. In ordinary speech, you would usually say something else depending on the situation, but in official texts заявитель is very typical.

Grammatically, here it is in the nominative singular because it is the subject of the sentence.

Предъявит is the future tense of the perfective verb предъявить.

So it means something like:

• will present
• will produce
• will submit

Why perfective? Because the sentence refers to a single completed action in the future: the applicant will present the certificate at that point.

Russian aspect matters a lot here:

• предъявлять = imperfective, process/repeated action
• предъявить = perfective, one completed act

Future forms:

• будет предъявлять = will be presenting / will present repeatedly or as a process
• предъявит = will present once, as a completed action

In official instructions, perfective is very common when the text describes what must happen as a concrete result.

Not exactly.

Предъявить is more formal and often means to present for inspection, to produce officially, or to show as required.

Показать is the general everyday verb to show.

So in this sentence, предъявит медицинскую справку suggests something like:

• the applicant will submit
• or present
• or produce a medical certificate

This is the kind of verb used for documents:

• предъявить паспорт = present a passport
• предъявить удостоверение = show/provide ID
• предъявить документы = produce documents

Using показать here would sound less official and less precise.

Медицинскую справку is in the accusative singular because it is the direct object of предъявит.

The applicant will present what?

• справку

Since справка is a feminine noun, its accusative singular form looks like this:

• nominative: медицинская справка
• accusative: медицинскую справку

The adjective changes too, to agree with the noun:

• медицинская → медицинскую
• справка → справку

So the whole object changes together.

Справка is a very common Russian word for an official note, certificate, or document confirming something.

The exact English translation depends on context. It can mean:

• certificate
• medical note
• official confirmation
• statement/document

Here, медицинская справка is usually best translated as:

• medical certificate
• doctor’s note
• medical document

Russian uses справка very broadly for official papers that confirm a fact.

Yes, Russian word order is flexible. This sentence uses a very natural formal order:

• По истечении месяца = time expression first
• заявитель = subject
• предъявит = verb
• медицинскую справку = object

This structure is clear and typical for official writing.

Other word orders are possible, for example:

• Заявитель по истечении месяца предъявит медицинскую справку.
• Медицинскую справку заявитель предъявит по истечении месяца.

But the original sounds especially document-like and organized: first the time condition, then who acts, then the action, then the document.

Yes, it is definitely formal and sounds like something from:

• a government form
• official instructions
• legal or administrative writing
• regulations

A person speaking casually would probably say something simpler, such as:

• Через месяц заявитель принесёт медицинскую справку.
• Через месяц нужно будет предоставить медицинскую справку.

The original sentence is not wrong in speech, but it sounds very official and written.

In this sentence, месяца is best understood as of a month, not specifically of the month.

Russian has no articles, so месяца by itself does not tell you a month versus the month the way English does. You understand it from context.

Here, the phrase по истечении месяца normally means after one month has elapsed. It is a general time period, not usually a specific calendar month.

If the text meant a specific month, the context would usually make that clear.

A practical pronunciation guide would be:

• По истечении месяца → pa istechÉniyi MÉsyatsa
• заявитель → zayavÍtel’
• предъявит → pred-YÁ-vit
• медицинскую справку → meditsÍnskuyu SPRAF-ku

A few useful notes:

• заявитель has stress on и: заяви́тель
• предъявит has stress on я́: предъя́вит
• The cluster in предъявит can feel difficult because of дъ
  • я
• справку is pronounced with a sound close to f in the middle: спрафку, because voiced в becomes devoiced before к

That last point is normal Russian pronunciation: spelling and pronunciation do not always match exactly.