The Understanding the Bible Commentary Series, published by Baker, is a re-branding of the the New International Biblical Commentary, formerly published by Hendrickson, which was a re-branding of the Good News Commentary series, formerly by published by HarperCollins.
GNC commentaries were first published in the 1980’s. Many NIBC commentaries published in the 1990’s were re-branded GNC volumes. Many UBCS commentaries published in the 2000’s were re-branded NIBC volumes. For example, Robert Mounce wrote the Matthew commentary in the GNC, NIBC, and the UBCS series. These editions have different publishers, different cover designs, and belong to series with different names, but the content in each book is the same. 
UBCS commentaries are noted for their easy-to-read format, their evangelical, though sometimes moderately-critical, approach to Scripture, and for their manageable size (many volumes are 300 to 400-page paperbacks) and for their affordability. Authors use the NIV translation.
These volumes are not technical so readers who do not have training in Hebrew and Greek can read the main body of the commentary without difficulty. The conclusion of each chapter includes a section called “Additional Notes” where the author includes brief discussion of transliterated Hebrew and Greek words as well as selective details about theology and history.
Please see how the UBCS series compares to dozens of other commentary series on the Bible Commentaries Comparison Chart.
Understanding the Bible Commentary Series (UBCS): Reviews
Many volumes in these series’ have received praise. Among Old Testament volumes, Iain W. Provan’s 1-2 Kings commentary is considered one of the best. The same is true of Christopher J. H. Wright’s Deuteronomy commentary and Gerald H. Wilson’s Job commentary.
Among New Testament volumes, Craig A. Evans’ Luke commentary has been well-reviewed, such as by London School of Theology professor Max Turner who wrote, “Craig Evans’ volume on Luke is a model of the series. The writer is as aware of the main questions which dominate Lucan scholarship today as he is of its methods and useful findings.”
Additionally, Gordon Fee’s 1-2 Timothy and Titus commentary has been well-reviewed such as by Southern Baptist Theological Seminary’s Thomas Schreiner who wrote that Fee’s commentary is “a model of clarity and organization and consistently reflects a judicious examination of exegetical issues…I think it is one of the best available [commentaries] on the Pastoral Epistles.”
Purpose of the Understanding the Bible Series
Publishers have described the purpose of these commentaries in different ways. Hendrickson Publishing wrote,
The New International Biblical Commentary series offers the best of contemporary scholarship in a format that both general readers and serious students can use with profit. The aim of the series is to provide reliable guides to the books of the Bible presented in a style that does not require formal theological education to understand. Based on the widely used New International Version translation, each volume in the NIBC presents an introductory chapter detailing the background of the book, its audiences, its authorship, its important themes, and other helpful information. 
Baker Academic wrote,
The Understanding the Bible Commentary Series helps readers navigate the strange and sometimes intimidating literary terrain of the Bible. These accessible volumes break down the barriers between the ancient and modern worlds so that the power and meaning of the biblical texts become transparent to contemporary readers. The contributors tackle the task of interpretation using the full range of critical methodologies and practices, yet they do so as people of faith who hold the text in the highest regard. Pastors, teachers, and lay people alike will cherish the truth found in this commentary series. 
New Testament Volumes
The links below go to Amazon, which sells new and used copies. Also visit Christian Book Distributors’ UBCS commentaries page to compare prices.
Publication dates reflect Baker Academic releases.
Matthew – Robert H. Mounce | Published: 2011
Mark – Larry W. Hurtado | Published: 2011
Luke – Craig A. Evans | Published: 2011
John – J. Ramsey Michaels | Published: 2011
Acts – David J. Williams | Published: 2011
Romans – James R. Edwards | Published: 2011
1 Corinthians – Marion L. Soards | Published: 2011
2 Corinthians – James M. Scott | Published: 2011
Galatians – L. Ann Jervis | Published: 2011
Ephesians, Colossians, Philemon – Arthur G. Patzia | Published: 2011
Philippians – F. F. Bruce | Published: 2011
1 and 2 Thessalonians – David J. Williams | Published: 2011
1 and 2 Timothy, Titus – Gordon D. Fee | Published: 2011
Hebrews – Donald A. Hagner | Published: 2011
James – Peter H. Davids | Published: 2011
1 and 2 Peter, Jude – Norman Hillyer | Published: 2011
1, 2 and 3 John – Thomas F. Johnson | Published: 2011
Revelation – Robert W. Wall | Published: 2011
Old Testament Volumes
Genesis – John E. Hartley | Published: 2012
Exodus – James K. Bruckner | Published: 2012
Leviticus, Numbers – W. H. Bellinger, Jr. | Published: 2012
Deuteronomy – Christopher J. H. Wright | Published: 2012
1 and 2 Samuel – Mary J. Evans | Published: 2012
1 and 2 Kings – Iain W. Provan | Published: 2012
1 and 2 Chronicles – Louis C. Jonker | Published: 2013
Ezra, Nehemiah, Esther – Leslie C. Allen and Timothy S. Laniak | Published: 2012
Job – Gerald H. Wilson | Published: 2012
Psalms – Craig C. Broyles | Published: 2012
Isaiah – John Goldingay | Published: 2012
Jeremiah, Lamentations – Tremper Longman | Published: 2012
Ezekiel – Steven Tuell | Published: 2012
Daniel – William Nelson | Published: 2012
Minor Prophets, Vol. 1 – Elizabeth Achtemeier | Published: 2012
Minor Prophets, Vol. 2 – John Goldingay and Pamela Scalise | Published: 2012