
It is a normal part of the process. It does not mean your claim was denied.
VA lists eight steps: 1 Claim received, 2 Initial review, 3 Evidence gathering, 4 Evidence review, 5 Rating, 6 Preparing decision letter, 7 Final review, 8 Claim decided.
VA says: if VA needs more evidence, or you submit more evidence, your claim goes back to Step 3, Evidence gathering. This applies when the claim is in Step 4, 5 or 6. VA also says you can submit evidence at any time.
VA's compensation site says the same thing another way: it is common for claims to return to the evidence-gathering phase when more evidence is needed.
Not always. VA says it asks for a claim exam only if it needs more information to decide your claim. Federal rules say VA will provide an exam or get a medical opinion when it decides one is necessary to decide the claim (38 CFR 3.159(c)(4)), and will order an exam when the file does not have enough medical evidence to rate the claim (38 CFR 3.326).
VA also says you may need more than one exam, for example if you claimed several conditions, if VA needs a follow-up exam to see how a condition has changed, or if you ask for a decision review.
Go to the exam. VA says missing it will delay your claim, and VA may decide the claim on the evidence already in your file, which could affect your benefits. VA lists good-cause examples such as a death in your immediate family, homelessness, hospitalization or a terminal illness.